kernel: backport Broadcom NVRAM driver cleanups

Refactoring of bcm47xx_nvram driver. It's used by bcm47xx and bcm53xx.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>

1 files changed, 75 insertions, 0 deletions

diff --git a/target/linux/generic/backport-5.10/800-v5.13-0005-firmware-bcm47xx_nvram-inline-code-checking-NVRAM-si.patch b/target/linux/generic/backport-5.10/800-v5.13-0005-firmware-bcm47xx_nvram-inline-code-checking-NVRAM-si.patch
new file mode 100644
index 0000000000..065543184f
--- /dev/null
+++ b/target/linux/generic/backport-5.10/800-v5.13-0005-firmware-bcm47xx_nvram-inline-code-checking-NVRAM-si.patch
@@ -0,0 +1,75 @@
+From f52da4ccfec9192e17f5c16260dfdd6d3ea76f65 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
+Date: Mon, 8 Mar 2021 10:03:20 +0100
+Subject: [PATCH] firmware: bcm47xx_nvram: inline code checking NVRAM size
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Separated function was not improving code quality much (or at all).
+Moreover it expected possible flash end address as argument and it was
+returning NVRAM size.
+
+The new code always operates on offsets which means less logic and less
+calculations.
+
+Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
+Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
+---
+ drivers/firmware/broadcom/bcm47xx_nvram.c | 25 +++++++----------------
+ 1 file changed, 7 insertions(+), 18 deletions(-)
+
+diff --git a/drivers/firmware/broadcom/bcm47xx_nvram.c b/drivers/firmware/broadcom/bcm47xx_nvram.c
+index 1d2271b1e07a..bd235833b687 100644
+--- a/drivers/firmware/broadcom/bcm47xx_nvram.c
++++ b/drivers/firmware/broadcom/bcm47xx_nvram.c
+@@ -42,18 +42,6 @@ static bool bcm47xx_nvram_is_valid(void __iomem *nvram)
+ 	return ((struct nvram_header *)nvram)->magic == NVRAM_MAGIC;
+ }
+ 
+-static u32 find_nvram_size(void __iomem *end)
+-{
+-	int i;
+-
+-	for (i = 0; i < ARRAY_SIZE(nvram_sizes); i++) {
+-		if (bcm47xx_nvram_is_valid(end - nvram_sizes[i]))
+-			return nvram_sizes[i];
+-	}
+-
+-	return 0;
+-}
+-
+ /**
+  * bcm47xx_nvram_copy - copy NVRAM to internal buffer
+  */
+@@ -85,7 +73,7 @@ static int bcm47xx_nvram_find_and_copy(void __iomem *flash_start, size_t res_siz
+ {
+ 	size_t flash_size;
+ 	size_t offset;
+-	u32 size;
++	int i;
+ 
+ 	if (nvram_len) {
+ 		pr_warn("nvram already initialized\n");
+@@ -93,12 +81,13 @@ static int bcm47xx_nvram_find_and_copy(void __iomem *flash_start, size_t res_siz
+ 	}
+ 
+ 	/* TODO: when nvram is on nand flash check for bad blocks first. */
++
++	/* Try every possible flash size and check for NVRAM at its end */
+ 	for (flash_size = FLASH_MIN; flash_size <= res_size; flash_size <<= 1) {
+-		/* Windowed flash access */
+-		size = find_nvram_size(flash_start + flash_size);
+-		if (size) {
+-			offset = flash_size - size;
+-			goto found;
++		for (i = 0; i < ARRAY_SIZE(nvram_sizes); i++) {
++			offset = flash_size - nvram_sizes[i];
++			if (bcm47xx_nvram_is_valid(flash_start + offset))
++				goto found;
+ 		}
+ 	}
+ 
+-- 
+2.26.2
+